DE3881175T2 - DECORATION ITEM AND ITS PRODUCTION METHOD. - Google Patents

Description

The present invention relates to a method of making substantially elongated decorative articles having a lens-like cap thereon and to the articles produced by this method of manufacture. In particular, it relates to a method and article in which a flowing plastic composition is poured onto a controlled-flat substrate to produce a decorative article which is free from optical distortion.

Mouldings of various configurations and decorative items and embiemes were used to decorate and protect car bodies in the automotive industry, as well as other surfaces in the passenger compartment. In recent years, the emphasis has shifted to the use of plastic mouldings that do not rust and that can be glued to the body without fasteners.

One such trim is shown in U.S. Patent No. 4,446,179, issued May 1, 1984 to Waugh and assigned to us. Waugh describes a decorative trim which may consist of an elongated decorative foil member having an impact resistant coating thereon having rounded edges and providing a lens effect on the foil member. An adhesive is used to attach the trim to the surface to be decorated. Another trim is shown in U.S. Patent No. 4,560,596, issued December 24, 1985 to Coscia and also assigned to the assignee of the present invention. Coscia describes a trim which includes a foil member having a decorative pattern on the top surface. The top surface is partially covered by a weather and impact resistant plastic coating with rounded edges and a lens effect on the foil part. The plastic coated portion of the foil part essentially covers the width of the automotive body part to be decorated. When the trim is attached to the body part, the uncovered end portions of the foil part are wrapped around the part. In the Waugh and Coscia processes, the substrate is held flat and horizontal, preferably by a vacuum hold-down device, during the casting and curing of the plastic coating or lens-like cap.

Recently, interest has arisen in the use of decorative articles to cover large, irregularly shaped surface areas and parts of an automobile. Previously, the decorative articles of the type shown in the Waugh and Coscia patents had a constant width and shape. This facilitates the uniform pouring of a flowing plastic composition onto the sheet part prior to curing the composition to Formation of the Plastic Coating. When a decorative article varying in width or shape is to be made by pouring a flowing plastic composition onto a substrate, it is important that sufficient amounts of the composition be deposited on all portions of the substrate. One technique which has been used in the past for pouring a flowing plastic composition onto a substrate in an irregular pattern is described in U.S. Patent No. 4,409,264, issued October 11, 1983 to Gilleo et al, and U.S. Patent No. 4,468,425, issued August 28, 1984 to Gilleo et al. The Gilleo et al patent suggests that an irregularly shaped region, described by a pattern of a low surface energy compound, such as a fluorochemical, printed onto the substrate surface, can receive a quantity of a soft resin. The substrate is then swung or tilted in various directions, causing the liquid resin to flow over the irregularly shaped area to the area boundaries. While this may be an acceptable technique for some area designs, it is not effective when the area to be covered with a flowing composition is significantly extended.

Our EP application No. 88 302 027.3 (EP-A-0282271) provides an improved method of making a decorative article in which a flowing plastic composition is poured and cured onto an elongated substrate region of varying width or shape to form a clear lens-like plastic cap. As with the Waugh and Coscia processes discussed above, the substrate is preferably held substantially flat and horizontal by a vacuum hold-down during the pouring and curing process.

However, it has been found that in some cases optical distortions occur in decorative items produced by these processes. The optical distortions, which could be described as an "orange peel" appearance, most commonly occur in large-scale decorative moldings with elongated areas of varying width or shape that are fitted to an automobile body panel, such as the vertical pillars found only on the rear of the front doors of many passenger cars.

Such pillars are known in the industry as "B-pillars" and "C-pillars". Paint or coating has become fashionable for covering the B-pillars and C-pillars to give a smooth, glass-like sheen. The use of decorative items with a lens-like cap, such as in Waugh, Goscia and our EP-A-0282271, are particularly suitable as a covering for B- and C-pillars because of the lens effect which enhances the surface beneath the lens-like cap. However, this is only true to the extent that there are no optical distortions in this coating.

There is therefore a need for an improved method for producing a decorative article in which a plastic composition to produce an elongated decorative article which is free from optical distortion.

A method of making decorative articles in accordance with the present invention is one which comprises a) providing a flexible substrate of about 0.005 to 0.025 cm (0.002 to 0.010 inches) thick vinyl resin having a first surface and a second surface, the flexible substrate being made by casting vinyl plastisol on a smooth surface to form a smooth cast-side surface as the first surface and an air-side surface as the second surface, adhering the substrate to a flat rigid release liner with a 0.005 to 0.013 cm (0.002 to 0.005 inch) thick layer of pressure sensitive adhesive through said first surface thereof, the substrate having an effective edge in a closed image on its second surface, the edge defining an area on the surface, b) applying a flowing plastic composition from a casting head to the second surface of the substrate in this area while the substrate is adhered to the release pad and is held flat and horizontal, whereby the flat, rigid, smooth-surfaced release pad holds the substrate flat and smooth during pouring and subsequent curing of the flowing plastic composition, and c) curing the plastic composition to form a clear plastic cap that visually enhances the appearance of the substrate as seen through the clear plastic cap.

The flatness of the substrate is controlled in part by the type of release pad to which it is releasably adhered. This release pad is a flat, rigid, smooth-surfaced, such as a rigid plastic part, which will keep the surface of the substrate to which it is adhered flat and smooth during casting and curing. No vacuum or adhesive hold-down is used. On the contrary, it has been found desirable to avoid such hold-down methods if the substrate is to be kept as flat and horizontal as possible and thereby avoid distortions induced during casting and curing. Rather, the release pad is the primary means of keeping the substrate flat and horizontal during casting and curing. Preferably, the release liner is a polyester sheet, such as a Mylar polyethylene terephthalate sheet, having a thickness of 0.018 to 0.030 cm (0.007 to 0.012 inches) and having a smooth silicone resin treatment on the release surface.

The flatness of the substrate is also controlled by the particular substrate used and its manufacturing process. That is, this substrate, which is a vinyl sheet such as a polyvinyl chloride sheet, has a thickness of 0.005 to 0.025 cm (0.002 to 0.010 inches), more preferably 0.008 cm (0.003 inches). The vinyl sheet is manufactured by casting vinyl plastisol on a smooth mold surface such as a smooth plastic or metal mold surface so that the as-cast vinyl sheet has a first surface which is a smooth "cast side" surface when removed from the casting surface. The second surface, or "air" surface, does not tend to be as smooth as the first cast side surface.

It is the second, less smooth, air surface of the vinyl sheet onto which the fluid plastic of the lens cap is poured. It has been surprisingly found that using the less smooth surface of the vinyl substrate as the decorative surface over which the lens cap is placed does not result in optical distortions when that surface is viewed through the lens cap, but rather minimizes such distortions. That is, the fluid plastic has been found to be self-adjusting in the manner that it smooths the less smooth surface, fills in the rough areas and voids, and upon curing produces an optically effective lens cap.

On the other hand, it has been found that the smoothness of the first surface (i.e., the one bearing the adhesive) adjacent to the car body is the key to avoiding optical distortion. Obviously, when a decorative article of the present type has a rough adhesive-bearing surface and is applied to the intended substrate, such as the "B-pillar" or "C-pillar" of an automobile, the pressure applied when applying the decorative article can expose the underlying roughness through the lens-like cap. An "orange peel" appearance is often produced.

However, such optical distortions do not appear when the first, molded surface is used as the adhesive-bearing surface and a relatively thick adhesive layer is used. The smooth first surface of the vinyl substrate retains its smoothness and the relatively thick adhesive helps to cover any imperfections in the portion of the automobile body to which the decorative article is attached. The adhesive is a pressure sensitive adhesive having a thickness of 0.005 to 0.013 cm (0.002 to 0.005 inches), and most preferably 0.008 cm (0.003 inches).

As mentioned, the substrate has an effective edge which preferably defines an elongated region on the second surface of the substrate. By elongated is meant either horizontally elongated or vertically elongated. That is, the elongated region generally has a greater length or height than width, depending on whether horizontally or vertically elongated. The effective edge may be formed by a coating of a substantially non-wettable material which is peripherally adjacent to the elongated region over which the lens-like cap is to be mounted.

The clear lens-like plastic cap may be formed of a flexible, abrasion-resistant plastic such as polyurethane. The flowing plastic is poured over the elongated region, flows to the effective edge of the region, and forms a positive Meniscus. The casting head may be a programmed articulated head or a series of heads which are operated in conjunction with each other as described in our EP-A-0282271.

The pouring head may be stationary and the substrate passed underneath. The rate of relative movement between the substrate and the pouring head may be substantially constant and the flowing plastic composition may be dispensed from the pouring head at a varying rate depending on the width of the region. The rate of relative movement between the substrate and the pouring head may vary depending on the width of the region, the flowing plastic composition being dispensed from the pouring head at a substantially constant rate.

A decorative article for covering an automotive part according to the present invention comprises a flexible substrate of about 0.005 to 0.025 cm (0.002 to 0.010 inch) thick vinyl having a first surface and a second surface, the flexible substrate being made by casting vinyl plastisol on a smooth surface to produce a smooth cast-side surface as the first surface and an air-side surface as the second surface, a substantially non-wettable material having a closed edge pattern on the substrate, the edge pattern defining an area on the second surface of the substrate and a border area of generally uniform dimension surrounding that area, a cured clear plastic cap in the area on the second surface of the substrate which improves the appearance of the substrate as viewed through the clear plastic cap, and means for securing the article to the automobile to provide a decorative covering thereof, the said edge region is bent around the edges of the part and the means for securing includes an approximately 0.005 to 0.013 cm (0.002 to 0.005 inch) thick layer of pressure sensitive adhesive on the first surface of the substrate.

The vinyl material may have a uniform decorative color, a decorative colored image, or have indicia printed thereon. The cured, clear plastic cap within the area of the substrate enhances the appearance of the substrate as seen through the cap. Even when attached, the decorative article of the present invention remains free of optical distortion.

For a better understanding of the invention, reference is now made to the accompanying drawings, in which

Fig.1 is a plan view of a decorative article made according to the present invention,

Fig.2 is an enlarged side view of the decorative article as seen from right to left in Fig.1,

Fig.3 is a sectional view showing the decorative article attached to an automobile part.

Reference is made to Figures 1-3 which illustrate a decorative article 10 embodying the present invention. This article comprises a flexible substrate 12 upon which is secured a cured clear plastic cap 14. The clear plastic cap 14, approximately 1.27 mm (50 mils) thick, creates a lens effect over the substrate 12. This enhances the appearance of any design or other ornamentation that may be created on the surface of the substrate beneath the clear plastic cap 14. Additionally, it has been found that the clear plastic cap 14 creates an improved appearance for the article even when the surface of the flexible substrate 12 is devoid of design or ornamentation, but rather is uniformly colored.

The flexible substrate 12 is a vinyl sheet, which may be metalized, having an approximate thickness of 0.005 to 0.025 cm (0.002 to 0.010 inches), and particularly preferred is about 0.008 cm (0.003 inches) thick black polyvinyl chloride sheet from 3M of St. Paul, Minnesota, USA. Such vinyl sheets are made by casting and curing a black colored polyvinyl chloride plastisol on a smooth polyester mold surface. When the cured vinyl sheet is removed from the mold surface, it has a first, "cast side" surface which is smooth and a second, "air side" surface which is less smooth.

The flexible substrate 12 is then adhered to a flat, rigid, smooth surface release liner (not shown) using an adhesive layer 22. A 0.005 to 0.013 cm (0.002 to 0.005 inch) thick layer of pressure sensitive adhesive, such as one of the acrylic pressure sensitive adhesives available from 3M of St. Paul, Minnesota, USA, and most preferably a 0.008 cm (0.003 inch) thick pressure sensitive adhesive, is cast onto a 0.018 to 0.030 cm (0.007 to 0.012 inch) thick silicone treated polyester release liner. A 0.003 inch (0.008 cm) thick pressure sensitive adhesive and a 0.007 inch (0.018 cm) thick silicone treated Mylar polyethylene terephthalate release liner are most preferred.

After the vinyl sheet is stripped from its mold surface, it is "laminated" to the adhesive-bearing release liner with the first, mold-side surface pressed against the pressure sensitive adhesive. This places the smooth side of the vinyl sheet directly on the smooth side of the release liner with a relatively thick layer of adhesive in between. The resulting laminate assembly is then cut to an approximate size for the decorative article to be produced. As mentioned, the preferred decorative article is one for covering an elongated automotive part such as a "B-pillar" or "C-pillar". Such decorative articles preferably have the edge-wrapping feature such as the type described in Coscia US Patent No. 4,560,596 and our EP-A-0282271. This edge-wrapping feature is shown in Figs. 1-3 where an elongated region 18 and an edge region 20 are shown. Other decorative objects of different shapes can also be produced by the present method.

The clear plastic cap 14 is formed by pouring a flowing plastic composition into an elongated region 18 on the surface of the flexible substrate 12, which is the second, air-side surface of the vinyl sheet. To hold the flowing plastic composition in the desired position during the pouring process and subsequent curing, a substantially non-wettable material 16 forming a closed edge pattern is provided on the flexible substrate 12. The thickness of the material 16 is exaggerated in Figures 2 and 3 for the purpose of clarity. The edge pattern circumscribes an elongated region 18 on the substrate and describes a border region 20 of generally uniform extent surrounding the elongated region 18. In the embodiment shown in Figures 1-3, the elongated region 18 increases in width from one end to the other end.

The substantially non-wettable material 16 may be any of a variety of materials known to restrict the flow of a flowing plastic composition across a substrate surface, such as various fluorinated polymers. A number of suitable materials are described in U.S. Patent No. 4,409,264. Preferred is a mixture of 50% polytetrafluoroethylene, 45% solvent, and 5% fillers, binders, and pigments. After application, the non-wettable material 16 may be allowed to dry for an hour or more. Alternatively, an effective edge for preventing flow of the flowing composition across the substrate surface may be provided by providing a ledge mechanically die-cut or otherwise formed in the substrate 12.

The molded plastic composition forming the clear plastic cap 14 is a thermosetting material which is weather resistant and will not yellow or become cloudy due to prolonged exposure to sunlight and which will withstand strong detergents. The molded plastic should also be abrasion resistant and impact resistant. A variety of plastics can be used for this purpose, but one which is particularly advantageous because it meets all of the above requirements is an impact resistant polyurethane of the type described in Waugh's U.S. Patent No. 4,446,179 and Coscia's U.S. Patent No. 4,560,596. Other plastics such as acrylic or epoxy resins can also be used. The plastic composition is preferably cured by heat or ultraviolet radiation, most preferably by convection heating at 43.3 to 65.6 C0 (110 to 150Fº). Depending on the plastic used, other means such as high frequency heating and air drying may be used to cure the plastic material.

During casting and curing, the flexible substrate 12 is held flat and horizontal due to the fact that it is releasably attached to the flat, rigid, smooth surface release pad during this stage of the process. This assembly is conveyed on a flat, smooth horizontal carrier through the casting station, then the curing oven to an unloading station. Preferably, no vacuum plates, adhesives or other hold-down devices are used during either casting or curing.

Following unloading, the decorative object can be punched to a finished geometry if necessary. It is then transported to the user still on the release base, such as to the automotive parts or assembly line. There, the decorative object is removed from the release base and applied to the elongated automotive part.

Figure 3 depicts the decorative article 10 attached to an automotive part 24, which may be, for example, the exterior vertical pillar found only on the rear of the front doors of many passenger cars. It should be noted that the rim region 20 overlaps the edges of the part 24, resulting in a neat appearance and facilitating the application of the article 10 to the part.

Claims (11)

1.A process for producing decorative objects (10), in which a) providing a flexible substrate (12) of approximately 0.005 to 0.025 cm (0.002 to 0.010 inch) thick vinyl resin having a first surface and a second surface, the flexible substrate (12) being made by casting vinyl plastisol on a smooth surface to produce a smooth cast side surface as the first surface and an air side surface as the second surface, the substrate being adhered to a flat, rigid, smooth surfaced release liner with a 0.005 to 0.013 cm (0.002 to 0.005 inch) thick layer of pressure sensitive adhesive (22) through said first surface thereof, the substrate having an effective edge (16) in a closed image on its second surface, the edge defining an area (18) on the surface, b) pouring a flowing plastic composition from a pouring head onto the second surface of the substrate (12) in said region (18) while the substrate is adhered to the release pad and held flat and horizontal, whereby the flat, rigid, smooth-surfaced release pad keeps the substrate flat and smooth during pouring and subsequent curing of the flowing plastic composition, and c) curing the plastic composition to form a clear plastic cap (14) that visually enhances the appearance of the substrate (12) as viewed through the clear plastic cap (14). 2. A method according to claim 1, wherein the edge (16) is formed by a coating of a substantially non-wettable material in an image which is peripherally adjacent to an elongated region (18). 3. A method according to claim 1 or 2, wherein the release pad is a rigid plastic part. 4. The method of claim 3, wherein the release liner is a polyester sheet having a thickness of about 0.018 to 0.030 cm (0.007 to 0.012 inches). 5. A method according to claim 3 or 4', in which the release substrate is treated with silicone resin. 6. A method according to any preceding claim, wherein the release liner is a silicone resin treated polyester sheet and the pressure sensitive adhesive is a 0.008 cm (0.003 inch) thick layer cast on the silicone resin treated polyester sheet. 7. A method according to any preceding claim, wherein the clear plastic cap (14) is formed from a flexible, abrasion-resistant polyurethane. 8. A decorative article (10) for covering an elongated automotive part (24) comprising: a flexible substrate (12) of approximately 0.005 to 0.025 cm (0.002 to 0.010 inch) thick vinyl resin having a first surface and a second surface, said flexible substrate (12) being made by casting vinyl plastisol on a smooth surface to produce a smooth casting side surface as said first surface and an air side surface as said second surface, a substantially non-wettable material having a closed edge pattern (16) on said substrate, said edge pattern defining a region (18) on said second surface of said substrate and defining a generally uniform dimensioned edge region (20) surrounding said surface (18), a cured clear plastic cap (14) in said region (18) on said second surface of said substrate (12) which improves the appearance of the substrate (12) seen through the clear plastic cap (14) and Means for securing the article to the automotive part (24) to provide a decorative covering thereof, said edge region (20) being bent around the edges of the part (24), and the means for securing including an approximately 0.005 to 0.013 cm (0.002 to 0.005 inch) thick layer of pressure sensitive adhesive (22) on the first surface of the substrate (12). 9. The article of claim 8, wherein the vinyl substrate is uniform in color. 10. An article according to claim 8 or 9, wherein the region (18) is elongated and increases from one end to the other end. 11. An article according to claim 8, 9 or 10, wherein the clear plastic cap (14) is formed from a flexible abrasion-resistant polyurethane.